This invention relates generally to seals for water pumps, and in particular, the present invention relates to a water pump seal which has the ability to reseal itself in the event of coolant seepage and/or leakage past the primary face seal.
Conventional water pump seals normally include a pair of donut-shaped face seals which are mounted between the rotating shaft and the fixed housing of the water pump. The face seals are normally contained within a casing which includes a spring for resiliently urging the face seals into an abutting and sealing relation to one another. The face seals are normally formed from an extremely hard material, such as ceramic. Any vehicle coolant that escapes through the primary face seal is channeled through an annular conduit located between the rotating shaft and the fixed housing toward a weep hole in the water pump housing. The weep hole channels the escaped coolant toward the ground so that it does not otherwise interfere with the engine.
Even when tile primary face seal is operating properly, small amounts of vehicle coolant seep past the face seal, through the annular conduit and out the weep hole. Oftentimes, this coolant seepage will leave a stain adjacent the weep hole as the coolant evaporates upon being exposed to the atmosphere. These stains are sometimes misinterpreted as a coolant leak which often results in the water pump seal being replaced even though the original water pump seal was working properly.
A much more serious problem develops when the water pump seal is actually defective thus resulting in coolant leakage past the face seal, through the conduit and out the weep hole. Loss of coolant through the face seal is generally much more severe in the case of leakage rather than normal seepage past a properly functioning water pump seal. Defective or otherwise leaky water pump seals must usually be replaced in order to prevent potentially catastrophic damage to the vehicle's engine.
What is needed is a water pump seal which impedes normal coolant seepage from reaching the weep hole and being misinterpreted as a coolant leak, and a water pump seal which seals itself in the event that the face seal becomes defective causing coolant leakage.